Piano construction



v March 12, 1929- c. MEHLIN 1,705,195

I PIANO CONSTRUCTION 3 Sheets-Sheet. 1

Filed Aug. 5, 1925 March 12, 1929. c. MEHLIN PIANO CONSTRUCTION- Filed Aug. 5, 1923 3 Shoots-Sheet 2 pm Z A 7 .H 2m

Patented Mar. 12, 1929.

UNITED STATES CHARLES MEI ILIN, OF FORT LEE, NEW JERSEY.

PIANO CONSTRUCTION.

Application filed August 3, 1923.

This invention relates in general to piano construction, and has for its object broadly the increasing or diminishing of the volume of a sustained tone at the will oi? the player.

The invention contemplates the provision in a piano of a sound chamber controllably communicating with the atmosphere and adapted to directly receive and amplify the vibrations of the sound. board itself.

Another important object of the invention is the provision, along with such a chamber, of easy means tor controlling the function of such chamber and this without the use of the. hands of the player.

A further important obi ect of the invention is the provision of such an arrangement which will require minimum change in standard piano construction.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the 'l ollmving description, which, taken in connection with the aecompanying drawings, discloses a pre ferred embodiment thereof.

()n the drawings,

Figure 1 is a top plan view of a grand piano;

Fig. 2 is a front elevation thereof, the legs being shown broken away;

Figs. 3 and 4 are large sections taken substantially on the lines and 4-4 of Fig. 1;

Fig. 5 is a section taken substantially on the line 5-5 of Fi 4:;

Fig. 6 is a bottom plan view of the piano body; and

Fig. 7 is a section taken substantially on the line 7-7 of Fig. 5.

While for the purpose of illustrating the invention it has been shown as incorporated in a. grandpiano, it will be readily manifest, as the invention is better understood, that it can with equal 'laeility be employed in pianos o t the upright construction.

Referring to the d rawings, reference character 11 indicates the piano rim, which is con1- posed in the present instance of an outer rim member 12 and an inner rim member 13 upon the latter oil which is mounted the sound board 14:. This sound board is fast about its perimeter to the rim and is cut away at 15 to provide a free edge 16 at right angles to the direction of the grain of the sound board and across its longest dimension. A sound chamber is provided beneath the sound board and, defined at the top by the sound board or vibrator itself, at the bottom by a second Serial No. 655,422.

board 17 and at the sides by the rim 11 of the piano and the usual rail 18 and sound board supporting block 19 which constitute the cross block. It will be noted that this second board 17 does not extend down as far as the bottom of the rim and, therefore, will in no way interfere with the leg block 18. This second board 17 is cut away at 21 to correspond with the cut away part 15 of the sound board, providing at this point commu nication with the atmosphere. A closure is provided for this chamber and in the present instance this closure is of vane type located at the opening 15 oi the sound board. Three vane members, numbered respectively 22, 23 and 2 1-, are shown on the drawing and each of these is aivoted at 25 in bearings 26 in a bearing block 27 carried by and forming a part of the rim member 13. The three vanes are connected together by a shutter connection 28 so that they may move conjointly and from the closed position shown in full line position in Fig. 7 to that shown in dotted lines. The lower vane member is provided with an arm 29 pivoted to a curved link 31 to a shortlink 32, in turn connected to one arm of a bell crank pivoted at 34. beneath the second board 17. A spring connected to the link 32 at one end and to a post 36 at the other, pulls the vanes toward closed position and mechanism is provided which is operable by the mere movement of the knee of a player for positively opening the vane closure to the extent and for such periods as may be desired in playing.

This opening or controlling mechanism includes a link 37 extending from the other arm 38 of the bell crank (already mentioned) to an arm 39 of a bell crank fixed beneath the key board or key bottom, the other arm 41 of this last mentioned bell crank is connected by a link 42 with an arm 43 of a lever pivoted at 44 beneath the key board or key bottom and having an end 41.5 extending out for engagement by a pivoted arm 46 arranged so that the knee of the player may engage the same.

The arm 4.6 is freely movable in a clockwise direction (viewing Fig. 6) to a position beneath the key board so that it is out of sight when it is not desired to use the sound chamher.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will beapparent that variene changes may bema'de' in the term, construction and arrangement ot the parts Without departing iroin the spirit and scope of the invention of sacrificing all or" its material advantages, the form hereinbefore described beingmerely a preferred embodiment thereof.

I claim:

1. In a piano, the combination of a sound boa-rd having a free edge, a second boardtherebeneath, piano parts co-operating with both'said boards to term a sound chamber,=-. and means located at said free edge for controlling communicationbetween said sound chamber and the atmosphere.

2. In a piano, the con'ibination of a plurality of sound boards spaced apart and torn'ied with tree edges ;pi2i no parts co-operating with thesoundboards to tornrasound chamber" andadjustable means for con trolling the extent of opening between said sound boards at saidfree edges.

3. In a'piano, the combination of a sound board having a'i're'e edge, piano parts co-operating With said board to form a sound chamber andan adjustable means for providing'a controllable opening for said sound chan'iber at said free edge. I

i. Ina piano, the combination oi? a rim, 9. soundboard mounted therein, second board beneath said sound board, said sound board andse'cond boardforming the upper and bottom'men'i'bers o1 a sound chamber, and a closure for said chamber pivotally mounted in said rimf 5. In a'piano,"the combination-of a piano rim, a sound board, a second board mounted therebeneath, said soundboard and said'sec- 0nd board'torming' top and bottom membe'rs'of a sound chamber, avaneclosure pivoted in said rim, a key board, a linkage system of links and bell crankscommunicatingbetweensaid closure and said hey board, and a member pivoted to the bottom or" said key board'and adapted, when in one position, to be'moved to actuate said linkage and, when in another, to be disposed entirely beneath said 3 key board.

6. In a piano the combinationott a piano rim and sound board supported on one side of said rim, a second board mounted on the other" side of said rim, said sound board and said second board forming top and bottom members of a sound chamber and havinga ii'ree edge, and a vane-closure pivoted in saidrinr between said sound board and said second board, said vane closure being controllable to restrict the sound from the sound chamber.

7. In a piano the combination oi? a piano rim and sound board supported on one'side of said rim, a second board mounted on the other side of said rim, said sound board and said second board forming top and bottom members of a sound chamber andhaving a free edge,"and a vane closure pivoted in said rim between the tree edges of the sound board and said second board, said vane closure being movableto'entir'ely close said sound chamber.

8. In a piano the combination of endless piano rim, a sound board secured to one side of said rim andhaving a free edge, a second board secured to the opposite side of said rim and having a free edge located opposite the free edge of the sound board, said sound board, said rinnand said second board torming a sound chamber, and manually controllable means positioned between th 'l'r-eecdges of saidsound-board and said second board for establishing communication" between the sound chamber and the atmosphere.

9.]In apiano the combination of an endless pianoirinn a sound'board secured to one side of said rim=and havinga free edge, a-sccond boardsecuredto the opposite side o'E said rim and having a free edge located opposite the free edge or the sound boars, said sound board, said rim and said second board forming a sound chamber, a plurality of vanes pivoted in the rimand adaptedto provide a closure extending between the ed es of said sound board and said second board, and means for controllingsaid-vanes to establish communication between the sound chamber and the atmosphere.

10. Ina piano the combination of an endless piano rim, a sound board securedto one side of said rim and having a free edge, a second boa-rd seeured'to the-opposite side ct said rim and having a free edge located'opposite the free 'ed -e' of the 'sound beard, said/sound board, said rim-and said second boar forming a sound chamben-a plurality of vanes pivoted in the 'rim' anc ladapted to provide a closure OXtGIIClllIgbBt-WQOD'thQ edgeso't said sound board and saidse'cond board, and means for controlling said vanes to establish communication between the sound chamber andthe atmosphere, said means including a member pivoted to the bottom of the key boardof the pianonnd'extending beyond the edge? thereof when in operative positiononly.

11. In a piano, in combination with the rim and leg block disposed thereunder and the cross'block, a sound board disposed at the upper end of said crossblock and rim and havin'ga free edge adjacentandspaced from said rim, a second sound board disposed in spaced relationbeneath said first sound board, said second sound board being located above the bottom of the rim and above the leg; block, said'secondsound board having a free edge registeringwith thatof the first sound board topi'rfiv-ide a sound opening communicating with theatmosphere and communicating with the chamber formed by the spaced sound board:

' CHARLES- MEHLIN. 

